Re. the 'is he the greatest fullback' qn, no I don't reckon. Very good overall, probably in the great class in attack, but prone to some critical errors (eg. lost us a world cup final, almost coughed up a gf against the eels... )
(a miserable grub from the purple ones, too, but most are agreed on that here)
'great' class fullbacks? (sorry, too young to pronounce on the little master) Changa, Wombat
near misses: mini, belcher, mick potter (as the absolutely always there with the right play player)
let's hope stewie can have a couple more seasons and get close to his best as he has the stuff to climb up this list.slater edges him in attack but stewie's overall quality is superior (I don't see him making those howlers in big games).